Reamer drill bit



June

D. ALFORD REAMER DRILL BIT Filed 1926' Q Patented June 7, 1927.

I UNITED STATES 1,631,449 PATENT caries.

i ALLEN 1:. mean, or'mmras, mixes.

DRILL an";

Application flled Deceinber e, 1920. serial Na-152,747.

This invention relates to improvements in reamer drill bits and in suchconnection it relates more particularly to the novel arrangement andconstruction thereof.

Heretofore in rotary drills it was possible at times to underream thehole made by the bit by means of reamers which were pro jecte by gravityfrom the drill stock or body. In such underreamers, however, as

the reamer body was droppedin the drill body the reamers werePI'OJQClIBd a short and defined distance beyond the drill.

It is of importance in drilling when the cap rock is reached that thehole be enlarged into a well-defined chamber and it is to accomplishthis purpose as well asto provide a tool for underreaming that? thepresent invention has been devised.

In the present invention two reamer bits are provided, each bit beingivoted at its inner end to a cylindrical hea ,carried by the drill body,which head is recessed to receive the bits. The head is so arranged thatit will move downward in the drill body by means of water, steam or airpressure, forcing the reamer bits outward at a more or less angularrelationship to the drill body, and a coiled spring, co-acting with thepressure, is adapted, when the pressure is released, to cause the bitsto resume a normal position in the head and drill body. Suitable meansare employed to gauge the reamer bits to the distance t ey are toproject outward before the pressure is applied.

'With the above and other minor,objects in View, the invention will bebetter andmore clearly understood by reference to the followingdescription, in connection with the accompanying drawings, and wherein:

Figure 1 is a view partly in section and partly in side elevation of areamer drill embodying the main features of the invention.

Figure 2 is a vertical sectional view, i1- e5 lustrating more in detailthe position of the spring and bits when the latter are fully extended.

Figures 3, 4, 5, 6 and 7 are cross-sectional views taken on lines 33,4-4, 5-5, 6-6

,60 and 7-7, respectively, of Figure 1; and

Figure 8 is an elevational view of a plug.

In the arrangement and construction of the invention there is provided adrill body 1 which is hollowedor interiorly chambered,

at the lower end being screw-threaded to r eof which 5 indicates thetop, and having a circular opening V 5* for the admission of ceive adrill bit 2. Inside'the drill body 1 are arranged the reamer bits 3-3,which are pivoted by a pin 4 to a hollow slidable head water underpressure, the bottom or lower end indicated at 6' formed integral with apin 7. This head is recessed to receive the reamer bits 3--3, the wallsof the recess being shown at 5". The top 5 of the head and its bottom orlower end 6 have projections 8--8 formed integral therewith and fittinginto a complemental groove or channel 9 and wherein the head rides whenthe bits are advanced outward, so that the reamer bits when projectedthron h the slots 3 will not rotate within the dri 1 body, but will turnwith said bodyin reaming out the hole.

Referring again to the pin 4, to which the reamer bits are pivoted, itwill be seen by reference to Figure 4 that these bits overlap eachother, and the pin whenfully advanced is enclosed in the drill body 1,its. ends supported by the recess walls 5". When so advanced the holesin the drill body into which the pin 4 is inserted are closed or pluggedby screws 4 and 4. Arranged to. encircle the pin 7 is a coil spring 10,one end resting against the under side of the hollow head, the other endof .the spring encircling a pin 11 and supported by the head 12 of thepin, which is screw threaded so that it may be advanced upward in thedrill body 1. Between the head 12 of the pin 11 and the drill bit 2 is aspace 13 to allow of suflicient room for the-head 12 of the pin 11 to bemoved up or down in the drill body 1.

To set or' gauge the distance the reamer bits 33 are to project throughthe slots 3, there .is provided a key 14' threaded to receiv a circularnut 15. The key 14 is placed on the to 5 of the head and the key turned,forcing the head downward,- the reamer bits being projected outwardthrough the slots o 3, the desired distance. The head 12'of the pin 11is then advanced until the pins 11 and 7 meet.. The key 14 is thenremoved.

When water-pressure is used the water-is forced downward through thedrill stem 16, 105 passing through the opening 5*.and thence throu h theopenings 6* and 12 to clean the, mud roin around the spring, etc. Watercan thus pass through the openin s, yet the pressure is sufficient whenthus imlnished I10 I an opening in its to tohold the pin 7 and the pin11 in contact and thus retain the bits in a rigid position 'forunderreaming. When air or steam resslida-ble head within the drill body,reamer bits carried by saidhead, said head having and a seriesof-openings in its lower en to admit water under pressure, the lower endof said head formed integrally with a downwardly projecting" in, amovable nut with an upwardly proecting pin below the upper pin, and acoil sipring encircling and resting on the shoulers of said pins.

2. A reamer drill comprising 'a hollow body, a drill bit on the endthereof, a slidable recessed head within said hollow body carryingreamer hits, a coil spring below said head supported b a nut and pm,erforations through sai head, nut and '11 bit for the admission of waterunder pressure to thereby contract said spring and project the reamerbitsoutwardlyat right angles to the drill body, and means for closingthe opening in the top of said head when applying steam or air ressure.

In testimony whereo I aflix my si nature.

ALLEN D. ALF RD.

